How does Lasix work? What will it do for me?

Furosemide belongs to the class of medications called diuretics. This medication is used to treat edema (fluid retention) that occurs with congestive heart failure and disorders of the liver, kidney, and lung. It is also used to control mild to moderate high blood pressure. It may be used in combination with other medications to treat more severe high blood pressure.

Furosemide works by increasing the amount of urine produced and excreted, and by removing excessive water (edema) from the body. The tablet form begins to work within an hour of being taken and usually lasts for 4 to 6 hours. The injectable form begins to work within ½ hour and lasts approximately 2 hours.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

How should I use Lasix?

The recommended adult starting dose for treating edema is 40 mg to 80 mg. If a satisfactory result occurs within 6 hours, the dose may be decreased or kept the same. If edema continues longer than 6 hours, the dose may be increased by 20 mg to 40 mg.

The recommended adult daily dose of furosemide ranges from 20 mg to 200 mg. Once the effective single dose has been determined, it may be taken 1 to 3 times a day.

When treating hypertension (high blood pressure), the dose of furosemide starts at 20 mg to 40 mg twice a day. Doses of 40 mg twice a day are generally considered the maximum dose to treat high blood pressure. If blood pressure hasn't been reduced enough with this dose, other medications may be added to further reduce blood pressure.

For children, the dose of furosemide used is based on body weight. The recommended dose is up to 2 mg per kilogram of body weight each day, divided into 2 to 4 equal doses.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones above, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

The contents of this site are for informational purposes only and are meant to be discussed with your physician or other qualified health care professional before being acted on. Never disregard any advice given to you by your doctor or other qualified health care professional. Always seek the advice of a physician or other licensed health care professional regarding any questions you have about your medical condition(s) and treatment(s). This site is not a substitute for medical advice.